Body fat Testing With Skinfold Calipers
The Skinfold caliper is a device which measures the thickness of a fold of your skin with its underlying layer of fat. By doing this at the key locations can be a quite accurate representative of the total amount of fat that is on your body, it is also possible to estimate the total percent of body fat on your body.
The diagrams show the locations of the areas for the measurements to be taken. Because of the location of the tests you will need someone who can do the measurements for you. It is important that the measurements are taken as close to the area's shown in the diagrams for each measurement.
How To Correctly Take Measurements
If you're right handed, pull out the fold of skin with the underlying layer of fat with your left hand and hold it with the fingers of the left hand. Then with the calipers in your right hand, place the jaws of the calipers as shown in the diagrams below. The jaws of the calipers should be about 1/4" (7.5mm) from the fingers of your left hand which continues to hold the fold of skin. Release the trigger of the calipers so the entire force of the jaws is on the Skinfold. Do not release the fingers of the left hand while taking the readings.
It is important to keep holding firmly the fold of skin with the fingers so that the calipers are measuring just the thickness of the fold of skin. You will notice that when you place the calipers on the Skinfold that the calipers will "creep" a little, after a few seconds the “creep” will slow down and this is the time that the measurement should be taken. You must note the reading on the scale before releasing any pressure off the calipers.
Taking Measurements & Calculating Your Percentage
Measure all four locations shown in the diagrams below and write down the readings on the calipers scale. It doesn’t matter what order you do the readings in. Add up the four readings. The % body fat can then be determined from the chart at the bottom of this page. You will notice one set of figures for males and one for females, make sure you use the right one!
You may also note that the charts do not have a line for every millimeter or column for every age group on the chart, to do this would make the chart very large. To get accurate figures it is necessary to interpolate. For example, a female in the 16-29 age groups could have a sum of 29mm for the four measurements. This is halfway between the 28 and 30 on the chart. The % body fat for 28mm is 18.6% and that for 30 is 19.5%. Interpolating halfway between would give approximately 19.0%. Another example would be a 40 year old male with a sum of 42mm for the four measurements. Referring to the chart for males we find % body fat listings for 40 and 45mm. 42mm is 2/5ths of the way between 40 and 45. The body fat for 48mm is 20.3%, and for 45mm it is 21.8%. Two fifths of the way from 20.3 to 21.8 is approximately 20.9%.
Where To Take The Measurements
Back of the arm (triceps):
The back of the upper arm, (Triceps). This is located halfway between the shoulder and elbow joints. The fold is taken in a vertical direction directly on the center of the back of the arm.
Front of the arm (Biceps):
The front of the upper arm, (Biceps). This is taken exactly the same as the Triceps, Figure 1, except it is taken on the centre of the front of the upper arm.
Back, below the shoulder blade (subscapular). This is located just below the shoulder blade. Note that the skinfold is taken at 45 degrees angle as shown on the diagram.
Waist (Suprailiac). This is located just above the iliac crest, the protrusion of the hip bone, a little towards the front from the side of the waist. The fold is taken approximately horizontally as shown on the diagram.
Durnin/Womersley Skinfold Body Fat Calculator
Durnin/Womersley Skinfold Body Fat Calculator
Normal Or Ideal % Bodyfat?
What is the correct or ideal % bodyfat? This is perhaps the most difficult question to answer. Not all people have the same ideal % bodyfat. It varies with age, sex, and genetics. One person might be better at a higher or lower bodyfat than another person of the same age and six. And the desirable bodyfat of athletes can vary depending on the sport. For example, swimmers seem to perform better at a higher % bodyfat than runners. But, some general guidelines can be given that are applicable to most people.
For men up to about the age of 30, 9-15% is good, from age 30 to 50, 11-17% is a good range, and from age 50 and up, 12 to 19%. A person should try to stay at or below the upper limits given, and a person near the lower limit would be described as lean.
For women, the range up to age 30 is 14-21%, from 30-50 it is 15-23%, and from 50 up it is 16-25%. Again it is desirable to be at or below the upper limit, and a woman near the lower limit would be lean.
It should be noted that the ranges given above are not averages for the US and UK populations, but are the desirable ranges. The actual averages for the populations as a whole are much higher because of the large number of people with % bodyfat well above the upper limits of the desirable ranges.